Polyarylates containing derivatives of the natural amino acid l-tyrosine

A method for the polymerization of polyarylates comprising:

• mixing equimolar quantities of:
• (a) a diphenol having a structure represented by the formula:
• ##STR12## wherein X is selected from the group consisting of --H, --NHL.sub.1, --NL.sub.1 L.sub.2,:
• ##STR13## Y is selected from the group consisting of hydrogen and ester groups having the structure:
• ##STR14## wherein L.sub.1, L.sub.2 and L.sub.3 are independently selected from the group consisting of straight or branched alkyl and alkylaryl groups containing up to 18 carbon atoms;
• and
• (b) a dicarboxylic acid having a structure represented by the formula:
• ##STR15## wherein R is selected from the group consisting of saturated and unsaturated, substituted and unsubstituted alkyl, aryl and alkylaryl groups containing up to 18 carbon atoms;
• together with a catalytic amount of 4-(dimethylamino)pyridinium-p-toluene sulfonate (DPTS) in a solvent for said polyarylate;
• and
• adding at least one molar equivalent per mole of carboxylic acid groups present of a carbodiimide, so that a polyarylate is formed comprised of recurring structural units represented by the formula:
• ##STR16## .